Obviously a fantastic job and y'all should be proud! Controls took a second to get used to but felt really nice once in the groove. I think a little bit of snap when you're next to enemies to take them over in, what, ghost? mode would be a nice touch, a few times i felt an enemy was unfairly dodging me when I thought I was colliding with it. Very minor gripe, most of the time the swapping felt really good. All the juice was really great, maybe the explosion particles are a slight bit over the top but whatever. Rather be drowning in it than parched for it :) the music was really good, the only thing i felt was lacking compared to the high quality of the rest of the game was sound effects - what's there is fine, but it'd be nice if there were... more. I understand if it's a stylistic choice to not have sounds for shooting, but the shooting itself could've had more impact, for instance.
Thematically I'm not personally convinced by the idea that there's no player, that we somehow are all the enemies, or that it really feels like "I am everywhere", though obviously everyone's interpretation of that is different. Not to say you aren't on theme at all, just I think it'd be really cool to see that aspect explored more - if we are all the enemies, why are we killing them? Is there like a bonus for keeping more of ourselves? What if we could actively swap between them? If there's no player, why are we the only ones with the teal possession ability? Just some thoughts, if you plan to develop this further.
Which, honestly, I hope you do, cause if this is what y'all can put out in three days I'd love to see what some more would produce. When can I buy the launch version? 😁